Fluid pressure-operated valve



Dec. 1,

Original Filed May 29, 1945 D. G. GRISWOLD FLUID PRESSURE-OPERATED VALVE 2 SheetsSheet l awe/whom D 1 5 D. e. GRISWOLD 2,661,023

FLUID PRESSURE-OPERATED VALVE Original Filed May 29, 1943 2 Sheets-Sheet 2 Gum/nu e Patented Dec. 1, 1953 FLUID PRESSURE-OPERATED- Donald G. Griswold, .El Monte, Galif ignor to Clayton Manufacturing. Company, Alhambra,

Calif.

Original application May 29, 1943, Serial .No. 489,007, new Patent. No. 2;44.7;4;0.8, dated Au;-

gust .17, 1 948;.

Divided; this; application August.15,,1947,- Serial No. 768,754.

1' Glaim. (Cl. 137-4388,)1

l The present invention relates to check valves and more particularly toan automatic check valve adapted to be used in a water supply line connected with a pump.

More specifically, the invention relates. to a highly sensitive, automatic check valve which will close completely" in response to the pressure on the outlet side of said valve when the pump is shut down and which: will not open until after the pump has built up a pressure on the inlet side of said valve which is greater than that in the line on the outlet side of said valve.

This application is a division of my copend-in application Serial No. 489,007, filed May 29,,L943, now Patent No. 2,447,408.

An object of the invention isto provide a check valve of large capacity which. is poweroperated to efiect both the positive full opening and full closing of the valve in accordance with pressure changes in the line on the inletv and outlet sides of said valve.

Another object of the invention. is, toprovide an automatic, power-operated check valve that will close at a predetermined rate, regard-lessof the difference in pressure on the inlet and outlet sides of said valve, and thereby avoid too-sudden closing of the valve with resultant line-shock.

Another object of the inventionv is to provide a pilot-controlled, power-operated check valve which is highly sensitive in its operation and yet is normally held in its full open position, in; order to prevent restriction orresistance to. the flow of liquid through the body of the valve, 'orheld'ful-ly closed in drip-tight relation.

Another object of the invention is to provide an automatic, hydraulically operated checkvalve which derives its operating fluid from either the inlet side or the outlet side of the valve, depending upon which side is subjected to the highest pressure.

A further object of the invention is to. provide, in a water pumping system, a flow control. valve having a pilot valve associated therewith which is operable in accordance with thev pressure differential on the inlet and outlet sides of said flow control valve, and. wherein operating .fl-uid :ior

efiecting power operation of the main valve can be taken by said pilot-valve from either the-inlet or outlet side of said flow control valve, depending upon which side is subjected .to the higher pressure.

A still further object of the inventionis to provide a pressure-responsive control means -for a hydraulically operated main valve .in which. the

2, ential, pressure. .on the inlet and outlet sides of saidmainvalve to. effect positive full opening or full closingoisaid'maihvalve in accordance with variations. in the di'fierent'i'al pressure.

Other and. further objects of the invention will. be. apparent. from the following description taken in conjunction with the accompanying in which:

Fig. I schematically illustrates a water supply system including a pump, and an automatic check valve and pilot control means constructed in accordance with the principles of the. present inventicn (the parts not being drawn to the same relative scale) Fig. '2 is a diagrammatic, longitudinal sectional view taken through the check valve and the. pilot valve.oflFig..,.l.;

'Fi'gfi'isa horizontalsectional view through the pilot valve taken-on the line 3-3 of Fig.v 2;

Fig, 4 isa scattered view of the pilot disc; pilot disc seatand iluid distribution base of the pilot valve, particularly showing the relative positions of. the ports in these parts; and

Fig. 5I'is an enlargedlsectional view through the pilot disc taken on the line 5-5 of Fig; 4.

Referring now to Figure 1 of. the drawings, the numeral [generally indicates the hydraulically operated main or check valve and the numeral 2 generally indicates the pressure responsive pilot valve for controlling said main valve. The check valve I is connected at its inlet end 3 to one end of a pipeline f and the opposite end of said pipeline is connected with the discharge outlet 5 of a conventional centrifugal pump 6. The outlet side 'I' ofthecheck valve I is connected to one end of a. pipeline '8, the: opposite endof which is connected with a. water storage tank 9 or other source of demand. It will be apparent from the for going, that the inlet side 3 of the check valve I. is subject to thepressurev of the fluid in the pump line 4 whereasthe outlet side 1 of the check valve is subject to the pressure of the fluid in the pipeline '8 which varies in accordance with V the demand.

control. is operable in accordance the dill'er- .5

The check valve l comprises a body it which terminates at its opposite ends in the previously mentioned inlet and-outlet ends 3 and 1, respectively. Thebody ID is provided with an internal partition wall. I! which divides the body into inlet. and outlet opening or: chambers 3 and l respectively. The partition H is provided with .a flange l'2 surrounding a circular opening l3 which establishes communication between the inlet opening or chamber 3 and the outlet opening or chamber 1%; ,An annular seat It rests upon the face of the flange i2 and is secured thereto by screws [5.

The check valve i also comprises an intermediate section it and a cover ll. The intermediate section it includes a central hollow cylindrical portion ii} and radially extending end flanges l9 and 26. The flange i9 is secured to the body it by a suitable number of studs 21 and a tight seal between the body it) and the flange i9 is obtained by means of a gasket 22 interposed between said body and said flange. The cover I! in turn is provided with a radial flange 23 secured to the flange 29 by a suitable number of studs 24 carried by the flange iii]. A main diaphragm 25 for controlling the opening and closing of the main valve l is marginally clamped between the flange 2B and the flange 23.

The intermediate section it is provided with a transverse wall as which forms a closure for the lower end of the hollow cylindrical portion IS. The wall 26 is centrally apertured and carrise a guide bushing 2? for a valve stem 2% Leakage from the main valve 1 along the stem 28 into the intermediate section i6 is prevented by a suitable stuffing box construction 29.

The valve stem 28 has a reduced, threaded lower end Bil which extends through an opening 3| in a closure member 32. A plain nut 33 and lock nut 3d securely fasten the closure member 32 to the end 30 of the valve stem 25. The closure member 32 is provided with an annular recess 35 which contains a ring as of suitable packing material adapted to engage and form a seal with a tapered face portion 3'! formed at the inner edge of the valve seat Hi.

The valve stem 28 has a second reduced portion 38 which extends through the diaphragm 25, a lower diaphragm supporting plate 39 received in the hollow cylindrical portion is of the intermediate member 16, and an upper diaphragm supporting plate MB. In this manner, the plate lil is disposed in an upper pressure chamber 4! and the plate 39 is disposed in a lower pressure chamber M formed in the hollow cylindri' cal portion it. The diaphragm supporting plates 39 and Ml are secured to the reduced portion 38 of the valve stem 28 by a plain nut d2 and a lock nut 63. A further reduced extension M is provided at the upper extremity of the valve stem 28 and extends through a guide bushing d5 mounted in a boss formed on the cover [1. The boss it has a passageway ll adapted to receive the end portion 44 of the valve stem 28 and said boss is further provided with a passageway 48 which establishes communication between the passageway d! and the pressure chamber ti. The escape of fluid through the passageway ll is prevented by a plug 42- threaded into the boss at. The upward movement of the valve stem 28, and consequently the movement of the closure member 32 away from the valve seat id, is limited by the engagement of an annular flange 50 on the upper diaphragm supporting member as with a complemental annular flange 5i projecting downward 1y within the cover H.

The pilot valve 2 comprises a housing 50 hav ing a fluid distributing base member t! secured to its lower face by suitable cap screws 82. A gasket as is clamped between the housing 59 and the base member 6% to prevent leakage therebetween. The base member 6! has a fitting 64 mounted therein which is connected with a T at. One side of the T 65 is connected with one end of a tube 66 and the opposite end of said tube is connected to a fitting bl which communicates with the inlet opening 3 of the main valve l. The opposite side of the T 65 is connected with one end of a tube 68 and the opposite end of said tube is connected to a fitting 65 which communicates with the outlet opening l of the main valve A conventional, flap type check valve it is connected in the tube 65 and a similar check valve 7! is connected in the tube 58. Thus, it will be apparent that operating fluid may pass to the fitting 64 of the base Si in one direction from the inlet opening 3 through the tube t5 and in one direction from the outlet opening l through the tube 63 depending upon which opening is under the higher pressure, the check valves it and H being arranged so that the flow from one tube cannot return to the main valve 1 through the other.

Operating fluid is conducted from the fitting 65 through a passageway ?2 in the base 5|, an opening 13 in the gasket 65, a passageway i i in the housing 60, through a strainer '15 and thence through a passageway it into a pilot disc chamber l'i' in the housing 50. The strainer 55 prevents the entrance of foreign matter into the pilot disc chamber l"! by way of the operating fluid and thus assures trouble-free operation and non-clogging of the pilot valve.

The pilot disc chamber T3 is formed at the lower end of the pilot Valve housing 63 and the open end 01"- said chamber is closed by a plate 18 serving as the seat for a pilot valve disc la. The pilot disc seat it may be secured to the pilot valve housing as in any convenient manner. As is best shown in Figure 4, the pilot disc seat '13 is provided with a central port 3t and a pair of ports 35 and 82 spaced a predetermined radial distance from the port and arranged upon radii 66 apart. It will be understood that the gasket 53 is provided with openings that register with the ports 30, SI and 82.

As is shown in Figures 4 and 5, the pilot disc 19 is provided with two through-passageways 83 and 84 adapted to be brought into registration with the ports 8! and 32, respectively, in the pilot disc seat '58. The pilot disc 19 is also provided with a U-shaped exhaust passageway 35, best shown in Figure 5. The exhaust passageway includes an axial leg portion te which con tinuously registers with the central port 29 in the seat 18 and another leg portion 85 which is spaced the same radial distance "from the axis of the pilot disc as the through-passageways 83 and M. t will be seen from Figure 4 that the through-passageways 83 and 8d are located at an angle of about 60 to either side of the exhaust passageway 85 so that it will be apparent that upon turning the pilot disc it through an angle 0: 60, the through-passage 83 may be moved out of registration with the port 81 of the seat it and the exhaust passageway 65 moved out of registration with the port 32 of said seat and into registration with the port Bl, simultaneously with the moving of the through-passageway 34 into registration with the port 82. in other words, the exhaust passageway 85 is adapted to alternately register with the ports 3! and 82 in the valve seat 18 and while said exhaust port is registering with one of said ports, one or the other of the through-passageways 83 or 84 is in registration with the other port in said valve seat.

The base member Si is provided with vertical passageways St 3H, and 52 which continuously register with the ports 30, 8! and 82 in the s er et pilot disc seat I8. The central passageway 80* communicates with a radial passageway 80 in the base III and this passageway in turn co'r'nmunicates with a pipe fitting 86 connected with a drain tube 89 discharging either into the atmosphere or a suitable drain. The-po'rtBI communicates with a radial passageway 81'" which in turn communicates with a pipe fitting 99 connected with one end of a conduit 9| the other end of which conduit is connected with a fitting 92 communicating with. the pressure chamber 4i above. the main diaphragm 25. The passageway 82* communicates with a radial pasageway' 52 which in turn communicates with a fitting 93 connected with one end of a conduit 94-, the opposits. end or which. conduit: is connected with a fitting 95 communicating with the pressure chamber M at the lower: side of 'themain diaphragm 25. The tube. 94 has: an adjustable, conventional needle valve fit connectedtherein arranged so. that it can control the rate of flow of operating fluid to the pressure chamber 41, and thereby definitely control the rate at which the main valve I is closed. The control: of. the

closing rate of the valve l isimportant, especially in pipe lines of large size where line shock is a serious problem.

As has been previously indicated, the operation of the pilot valve is controlled in accordance with the pressure difierential in the inlet and outlet chambers 3 and I of the main valve I. This is accomplished by incorporating a pressureresponsive pilot diaphragm I in the pilot valve housing 69. Thus, as shown. in Figure 2,. the pilot valve housing 60 is provided. with a compartment [ill which is connected by a pipe I02 with the outlet opening I of the main valve. A cap "13, which is secured to the housing 66 by screws I64, clamps the diaphragm H39 in place and is provided with a compartment Hi connected: by a pipe. I06 with the inlet opening 3 of the main valve. Thus, the pilotdiaphragm I 00 has its opposite sides exposed to the pressure in the inlet and outlet openings 3 and Hot the main valve I. V

The pilot diaphragm I00 is disposed between diaphragm supporting plates Iii-I and N38 secured to a reciprocable rod- I09 by a nut III). On'e'end of the rod I09 is slidably supported in a recess III in the cover I03 and the opposite end of said rod is supported in a recess H2 in the housing 69. The rod I09 is provided with a series of annular ridges H3, best shown in Figure 3. The ridges IIS mesh with the teeth of a gear H4 mounted upon the upper'end of'a pilot disc drive shaft H5. The shaft II5 extends through abore I IS in the pilot housing 69 and is packed against leakage by a stuifing box III so that fluid from the pilot disc chamber I9 cannot leak out along the shaft H6 and into the compartment WI, and vice versa. The lower end of the shaft I16 carries a drive washer H8 (Fig. 2) provided with pins II9 adapted to extend into apertures I29 (Fig. 4) in the pilot disc I9 to provide a driving connection between the drive washer H8 and said disc. A spring I2I disposed between the drive washer H8 and the pilot disc I9 urges the pilot disc downwardly to hold said pilot disc against its seat, whereby foreign matter is prevented from getting between said disc and seat should the fluid pressure fail in chamber II. The upper end of the shaft H6 is received in a plug I22 threaded into the housing 69.

Figure 2 shows the pilot diaphragm Hi9 flexed toward the right, as when the pressure in the outlet opening I of the main valve I exceeds the pressure in the inlet opening 3 of said main valve I and at which time said main valve should be closed. The flexing ofthe diaphragm I00 toward the right necessarily will have caused a shifting of the rod Its to the right with the resuit that the ridges H3 cause the gear Ht and its associated pilot drive shaft III; to rotate counter-clockwise through an angle of 60 to take the position shown in Figure 4. Such movement will position the leg of the U- shaped exhaust passageway 85 0f the pilot disc re in registration with the port 82 of the pilot disc seat I8 and the through-passageway 83 will register with the port 8L Operating fluid under pressure can then pass from the pilot disc chamber 553 through the through-passageway 83 of thepilot disc I9, port 8!, passages SI and 8| b in the base member 6i, through the fitting 99', conduit ill and fitting into the upper portion of the pressure chamber :ii to thereby gradually fill said chamber and flex the diaphragm 25 downwardly, forcing the valve stem 28 to move in a similar direction and seat the closure member 32 against the valve seat It to cut oif flow between the inlet and outlet openings 3* and I respectively, of the main valve. The needle valve es connected in the conduit tl will limit the rate at which operating fiuid can fiow from the pilot disc chamber is into the pressure chamber ii and thereby positively control the rate at which the main valve I will close.

Simultaneously with the introduction of operating fluid under pressure into the chamber 4| to effect closing of the main valve, spent operating fluid is exhausted from the pressure chamber di at the lower side of the diaphragm 25. Thus, spent operating fluid leaves the pressure chamber di through the conduit 96, passageways 22 82 in the base member El, port 82 in the pilot disc seat 28, through the U-shaped exhaust passageway 85 in the pilot disc I9, axial port 89 in the pilot disc seat I8, then through passages 36 and 8t in the base member GI and finally into the drain tube 89.

It will also be apparent that when the pressure on the inlet side 3 of the valve I exceeds thepressure on the outlet side i of said valve,

when the pump 6 has been started, the pressure in the'inlet opening 3 of the main valve I will be communicated to the compartment m5 of. the pilot valve housing til through the pipe iii-t and the pilot diaphragm Iilll will be flexed toward the left, as viewed in Fig. 2. Such flexing of the diaphragm Idii causes shifting of the rodits toward the left with the consequent rotation of the gear II 4, shaft H5 and pilot disc it clockwise through an angle of 60 to position the U-shaped exhaust passageway 85 of the pilot disc-id in registration with the port 8| in the pilot disc seat it. This same movement will position the through-passageway 84 of the pilot disc is in registration with the port 82 in the pilot disc seat ?8. As a result, operating fluid under pressure to sheet opening of the main valve 5 will then flow from the pilot disc chamher I? through the through-passageway 84 in the pilot disc Iii, port 82 in the pilot disc seat 78, passages 82 and 82 in the base member SI, and then through the conduit 94 to the pressure chamber M at the lower side of the diaphragm 25, thereby eifecting upward movement of the valve stem 28 with the consequent opening of the main valve I. Simultaneous with the introduction of operating fluid under pressure into the chamber 4P spent operating fluid is exhausted from the chamber 41 through the conduit 94, passages 81 and 81 in the base member 6 I port 8: in the pilot disc seat 18, through the U-shaped exhaust passageway 85 and the pilot disc 73, and thence through the port 39 in the pilot disc seat 18, passageways St and 80 in the base member 61, and tube $39 to the atmosphere or any suitable drain.

It will also be apparent that the main valve I is maintained in either its fully open or fully closed position and that the closure member 32 of the main valve does not flutter between open and closed position while the pressure differential varies or changes from one side of the valve to the other. Thus, the pilot diaphragm 180 must be in its substantially fully flexed position either toward the right or toward the left to align the passageways in the pilot disc 9 with the ports in the pilot disc seat i8. In other words, the main valve 1 will remain fully closed until the pilot diaphragm Hi8 has been flexed toward the left a distance suflicient to rotate the ilot disc through an angle of about 60. When the shaft H has been rotated to an intermediate position, say through 30, it will be evident that none of the passageways in the pilot disc is lies in registration with the ports 81 and 82 in the pilot disc '58 and, therefore, no fluid is either admitted into or drained from the pressure chambers 45 and M and hence the main valve i will remain closed until the U-shaped exhaust passageway 85 registers with the port 8! in the pilot disc seat 58, whereupon the main valve 1 will open in the manner before described. Similarly, the main valve 1 will remain fully open until the U-shaped exhaust passageway 85 has been shifted to a position in registration with the port 8'2 to efiect full closing of said main valve.

It will be understood from the foregoing, that the main check valve 1 is operated automatically in response to slight pressure variations in the inlet and outlet openings or chambers of the main valve, and that the main valve, contrary to the operation of conventional check valves, assumes either a fully open or fully closed position in accordance with the changes in the pressure differential. It will be obvious from Fig. 2 that when the valve 1 is in its fully open position, the closure member 32 will be retracted into the slightly larger, circular, central opening in the body it directly above the seat 84, and thus assumes a position wherein it least obstructs flow through the valve.

Having thus described the invention, what is claimed is:

I claim:

A fluid pressure operated valve, comprising: a body having inlet and outlet chambers disposed in horizontal axial alignment, a bottom wall portion, an upright partition extending from said bottom wall portion and including a horizontal offset providing a seat for a closure member between said inlet and outlet chambers, and having a circular central opening above said seat; a generally spool-shaped intermediate section above said body, said spool-shaped section having horizontal flanges at the opposite ends thereof and an integral transverse wall forming a closure for said opening in said body lying in a plane substantially common to one of said flanges; a cover above said spool-shaped section; a flexible diaphragm disposed between said cover and the other flange of said spool-shaped section cooperating with said cover to form an upper pressure chamber and cooperating with said spoolshaped section to form a lower pressure chamber in non-communicatin relation with said upper pressure chamber; a valve stem slidably extending through said transverse wall; means carried by said transverse wall and slidably engaged by said valve stem to form a fluid-tight seal around said valve stem; a circular closure member carried by the lower end of said valve stem, said closure member being slightly smaller than said central opening and having a path of movement from closed to open position of such extent as to be retractable into said central opening to minimize obstruction to flow and being engageable with said seat to shut on the flow between said inlet and outlet chambers when in its advanced position; means connecting the upper end or" said valv stem with said diaphragm; and means for admitting operating fluid under pressure into and for exhausting spent operating fluid from said pressure chambers.

DONALD Ga GRISVVOLD.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 249,578 Boyle Nov. 15, 183-1 412,789 Probert Oct, 15, 1889 615,381 McIntosh Dec. 13, 725,893 Truman Apr. 21, 1993 828,680 Quick Aug. 14, 1986 1,131,69 Fulton Mar. 16, 1915 1,181,010 Hoyt Apr. 25, 1915 1,302,538 Galick i /lay 1919 1,347,192 Tygard July 20, 1920 1,410,098 Hamilton Mar. 21, 1922 1,480,942 McKee Jan. 15, 1824 1,583,122 Bryant May 4, 1926 1,871,044 Crosthwait Aug. 1932 2,158,068 Grove Iviay 16, 1939 2,214,963 J'urs Sept. 17, 1849 2,377,227 Griswold May 29, 1945 

